There are many types of speaker enclosures, and each enclosure type can affect how sound is produced by the speaker. A transducer is mounted within the speaker enclosure, the transducer having a vibrating diaphragm for emitting sound waves in front of the diaphragm. As the diaphragm moves back and forth, rear waves are created behind the diaphragm as well. Many speakers take advantage of these rear waves to supplement forward sound waves produced by the diaphragm. In vented enclosures, the enclosure has a port, and the backward motion of the diaphragm excites the resonance created by the spring of air inside the speaker enclosure and the air contained within the port. The length and area of the port are generally sized to tune this resonant frequency.
Typically, current vented loudspeaker systems do not utilize the port as a source for cooling of internal speaker structures. In some cases, heat sensitive internal components may be placed in the vicinity of the port internal opening so that the high air velocity generated by the port at system resonance can offer additional convective cooling. However, this is difficult to do since these components must be placed far enough away not to disturb the port air flow, thus minimizing the cooling. Often, it is simply impractical to mount the components near the port opening.